


sesuReQUEST Prompts (Sanscest flavors)

by SesuRescue (Kigachan)



Series: Tumblr Requests and Prompts [5]
Category: Undertale (Video Game)
Genre: Alternate Universe - Swapfell, Alternate Universe - Underfell, M/M, Other Additional Tags to Be Added, Red/Razz, Selfcest, Ships in title, Tags In Each Chapter, kustard - Freeform
Language: English
Status: In-Progress
Published: 2018-05-18
Updated: 2018-09-22
Packaged: 2019-05-08 12:07:04
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 6
Words: 6,753
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14693895
Author URL: https://archiveofourown.org/users/Kigachan/pseuds/SesuRescue
Summary: This is the Sanscest shipping work!





	1. Kustard- "Stop texting me weird stuff so late at night"

**Author's Note:**

> Below are links to the other Prompt Works:  
> [ MISC Flavor ](https://archiveofourown.org/works/14693616/chapters/33952551)  
> [ Fontcest Flavor ](https://archiveofourown.org/works/14693337/chapters/33951684)  
> [ Papby/Papysansby Flavor ](https://archiveofourown.org/works/14693118/chapters/33951141)  
> [ Papcest Flavor ](https://archiveofourown.org/works/14693454/chapters/33952071)  
> 

**Summary for the Chapter:**

> Drunk Red likes shitty memes, pass it on

**Notes for the Chapter:**

> crysta-cub asked: **152 I think its TwistedFell? If you don't wanna do that pairing maybe[ Kustard? ](https://sesurescue.tumblr.com/post/169922674905/152-i-think-its-twistedfell-if-you-dont-wanna-do) ** From this [prompt meme ](https://sesurescue.tumblr.com/post/169351233610/nearly-200-writing-prompts-feel-free-to-reblog)
> 
> Pairing: Sans x Underfell!Sans (Red)
> 
> Tags: Drunk Red, Shitty memes, lazy text formats

Sans had been doing his favorite thing in the world, sleeping, when his phone buzzed with the arrival of a text. He turned over, eye lights brightening from their previously dark state, as he tried to figure out who the hell would be texting him at…whatever time of the night it was. It couldn’t have been Papyrus; he was downstairs watching television, probably Mettaton or something. Oh, it was probably Red, Sans decided, and a quick check of his phone confirmed that it was, in fact, his boyfriend.

Bae:  _heyyyyyyy_

If there was anything he knew about Red, it was that if he was texting Sans this late at night, that meant he was drunk. It wasn’t that he didn’t like when Red got drunk, in fact, it was pretty hilarious, but he tended to keep Sans up late with odd texts and surprisingly deep philosophical questions. If it had been any other time of the day he would’ve been happy to entertain Red, but today he just wanted to sleep.

He decided to ignore the text, stashing his phone underneath the pillow. Maybe if he didn’t answer, Red would think he was sleeping and stop texting him.

Unfortunately, his phone buzzed a few minutes later, muffled slightly by the pillow underneath him, but still noticeable. It buzzed again, and again, and a third time. Sans sighed; he knew it wouldn’t be that easy. Pulling the phone back out, Sans sat up in bed, slouching against the wall as he checked his messages.

Bae:  _snsssssss_

Bae:  _snssssssssss r u there????_

Bae:  _sanssssssssssssss it’s important_

Bae:  _bby pls i need ur help_

Sans sighed, typing out a reply.

Sans:  _sup? you okay?_

Bae:  _nooo it’s awful pls help_

Sans:  _okay i’m here. what do you need?_

Sans waited for Red to get back to him, feeling the comforting allure of sleep calling to him again. He debated giving in, just falling asleep slumped against his wall when he received a reply from Red.

Shaking off the fatigue, Sans opened the message, pausing as he stared at the image on his screen. It was a picture of two identical cartoon cats, one in front of the other. The first one had a pair of pants painted shittily over the bottom half of its body across all of its legs, and the second one had a pair of pants painted over the back half of its body, covering the hind legs and rear. A caption across the top read: ‘If a cat wore pants, would he wear them like this, or like this?’

“…what the hell?” he mumbled, typing out a response.

Sans:  _red what the hell_

Bae:  _pls sns i can’t decide_

Sans:  _it has to be the second one, right?_

Bae:  _i thght so 2, butt they hve 4 legs sns. 4. would they not wnt 2 cvr all of their legs??? Its 2 deep sns_

…What the actual fuck. Sans sighed, rubbing his sockets with his hands. Guess he better take care of this now or he’ll be getting messages all night. He dialed Red’s number, slowly slipping back into bed as he waited for the line to connect.

“ _y’ello_.” Red’s voice was loud, prompting Sans to pull the phone away from his skull. There was a lot of noise in the background, probably a rowdy bar night.

“ **stop texting me such weird shit so late at night** ,” Sans said, and then hung up the phone. He tossed it towards his pile of dirty socks in the center of the room where he wouldn’t hear it and pulled the covers over his head.

Unfortunately, he ended up staying awake all night thinking about whether cats actually would wear pants at all, nevermind how they would wear them. 

**Notes for the Chapter:**

> Thanks for reading! <3 feel free to bother me at my NSFW tumblr: [Sesurescue](http://Sesurescue.tumblr.com)


	2. Red/Razz - "Are you Flirting with me?"

**Summary for the Chapter:**

> sometimes red’s a good guy

**Notes for the Chapter:**

> crysta-cub asked: **56...has anyone paired[ Red and Razz](https://sesurescue.tumblr.com/post/169942811485/56has-anyone-paired-red-and-razz-that-might)... That might be funny ** From this [prompt meme ](https://sesurescue.tumblr.com/post/169351233610/nearly-200-writing-prompts-feel-free-to-reblog)
> 
> Pairing: ...RazzCherry? RottenCherry? (Underfell!sans x Swapfell!sans)
> 
> Tags: tiny bit of hurt/comfort, background mapleblossom/maplepuff?, mention of spicyhoney

Razz stepped through the portal to the Tale universe, Slim only a few steps behind him as they stood in the middle of the forest. After a quick check of the area (it wasn’t necessary, with this being a more harmless universe than the one he was accustomed to, but habits were hard to break), the two of them headed for Snowdin and the Tale brother’s house.

A few days ago, both he and Slim had received a text from the original Papyrus, inviting them over for a movie night with their other alternates. At first, Razz had planned to refuse. He had no interest in frivolous things such as movie nights, but he knew that his brother was enamored with the original version of himself for some reason, so he accepted the invitation. Despite how he may have projected himself to the public on a day to day basis, he did care about his brother’s happiness, so if he had to give up a few hours of his night to help Slim then so be it.

After a brisk walk through the snow, Razz and Slim made it to the front steps of the Tale brother’s house. Razz knocked on the door, and not even a few seconds had passed before Papyrus opened the door, ushering the two of them inside. “RAZZ, SLIM, HELLO! WE’RE STILL WAITING ON HONEY AND BLUE, BUT EDGE AND RED ARE ALREADY HERE. PLEASE, MAKE YOURSELVES COMFORTABLE!”

Razz winced at the volume of Papyrus’ voice, but the look on his brother’s face kept him from making a scene. He elbowed Slim in his ribs softly, flashing him a thumbs-up before stalking over to the couch and sitting down. A scowl replaced his previous soft expression as he crossed his arms, making himself appear as hostile as possible so no one would bother him. It actually worked for a bit, much to Razz’s surprise. Sans kept a wide berth around the area where he sat, choosing instead to doze off in front of the fireplace, and Edge went into the kitchen with Papyrus and Slim to help them prepare snacks for the movie night.

The only person who didn’t manage to take the fucking hint was Red, who decided to sit on the couch right beside him. It would’ve been manageable if he had just sat there and kept to himself, but of course Red had to start  _talking_  to him.

“what’s with th’ long face? ya look constipated.”

Razz turned to look at Red, disbelief on his face. “We can’t even get constipated, you idiot.”

“whoa, don’t get yer panties in a bunch, just makin’ conversation,” Red said, hands up in surrender.

Razz let out a ‘hmph’ sound and crossed his legs, angling himself away from Red. “I have no interest of talking to anyone here. Didn’t even want to come here,” He mumbled under his breath.

“man, tell me about it,” Red sighed. “boss always drags me out ta these things when all i wanna do is sleep. kinda surprised yer here, ta be honest.”

“I came as a favor to my brother,” Razz said, features softening slightly as he glanced towards the kitchen door.

Red followed his gaze, browbone furrowing slightly. “oh, yer bro like paps or somethin’?”

“I…yes, how did you–”

“i know that look in yer eye, felt the same when boss started pursuin’ honey.”

Razz let his mask slip slightly, turning to Red with a sigh. “I’m happy for him, but–”

“ya feel lonely, i get ya.”

Oh, that’s what that feeling was. Razz hadn’t been sure how to describe the pit in his SOUL that had appeared when Slim first talked to him about his infatuations with Papyrus, but now he knew. Loneliness. He brought a hand up to his chest, brushing his phalanges against the space where his SOUL lay beneath his ribs.

Red hopped off the couch, brushing off his jacket. “hey, u wanna get out of here?”

“What? To where?” Razz asked.

“anywhere, everywhere. we could go ta grillbz’s, maybe even back ta my place so i can help ya get that stick that’s always in your butt.”

“I do  _not_  have a stick in my butt!”

“oh, did ya lose it? i have one ya can use.”

“What does that even–wait,  **are you flirting with me**?” Razz sputtered. Red guffawed, slinging an arm around Razz’s shoulders.

“ya are kinda cute, and i definitely wouldn’t mind takin’ ya for a ride. wanna get drunk and make bad decisions?”

Blushing, Razz looked away from Red with a frown. “You can take me out to Grillby’s for exactly _one_  drink and burgers, but that’s it.”

“deal. let’s get outta here.”

Razz cast one last look towards the kitchen before following Red out the door, trying (and failing) to hide the small smile that graced his skull.

**Notes for the Chapter:**

> Thanks for reading! <3 feel free to bother me at my NSFW tumblr: [Sesurescue](http://Sesurescue.tumblr.com)


	3. Kustard for Kay

**Summary for the Chapter:**

> Red bought some a little special for his cute boyfriend <3

**Notes for the Chapter:**

> This is for Kaysins who is amazing and wonderful and awesome and made me a super hella cute gif <3 They wanted some [fluffy kustard](https://sesurescue.tumblr.com/post/174567142724/kustard-for-kay) with body worship and a smol, insecure Sans
> 
> Pairing: Kustard (Sanscest) - UF/UT Sans  
> Tags: Bara Red, Smol Sans, Lingerie, Full ecto-bodies, body worship, small dick sans

“are you sure this is what you want me to wear?” Sans asked. His hands twitched at his sides, inching their way closer to his middle before he caught himself and kept them down.

Red hummed as he took in the sight of his smaller boyfriend on the bed, clad in a lingerie set that he had purchased online, just for him. “hell yea, babe, yer gorgeous.”

And he was, actually far more gorgeous than Red had expected when he first saw the set. He had only bought the purple see-through babydoll set because it was the only color left (originally he wanted Sans to be wearing red, for obvious reasons), but he was pleasantly surprised with the results. The purple color complimented the blue tint of his ecto-body well, and the actual outfit itself flowed nicely over Sans’s curves, with a little opening down the front to show off the alluring image of the matching panties.

Red had to stop himself from drooling as he caught a peek of the small bulge in the underwear; it was much too early to go straight there. Instead, he let his gaze wander further up to Sans’s ample chest, his large tits barely contained by the flimsy material. He knew he just bought this outfit, but Sans wouldn’t be upset if he ruined it so soon, would he?

He glanced up at Sans’s face, catching the nearly indecipherable twitch of his grin when their eyes met for a split second, and then Sans averted his eyes with a blush. Red inwardly sighed; Sans still wasn’t feeling completely confident in his body, was he? Well, Red would just have to change his mind, wouldn’t he?

Red adjusted himself on the bed so that he was hovering over Sans, flashing him a wicked grin as he ran his hand over the bottom of Sans’s thighs. With every stroke of his phalanges over the flesh, Sans shivered underneath him, encouraging him to take his touch up a little higher. “sweetheart, yer know how beautiful you are right?” Red asked. “yer so soft and perfect.”

“i think i’m more doughy than anything,” Sans remarked with a dry chuckle as he patted his sides. He sat up slightly to take a look at himself, frowning slightly. “Look at this, i’m practically spilling out of this outfit,” he said, gesturing to his top.

“oh my god, that’s just cuz yer tits are so huge,” Red guffawed. He bent down to capture Sans’s mouth in a quick kiss, taking advantage of the position to squeeze his breasts. Sans moaned into the kiss predictably, giving Red the opportunity to deepen it with his tongue. The wet sounds of their sloppy makeout rang through the room as they got more into it, and at some point, Red had laid down fully on the bed over Sans, giving him free rein to play with all of Sans’s luscious curves. And, of course, he just wouldn’t be himself if he didn’t slip in some praise.

“I love yer so much, babe. i love how squishy your boobs and stomach are, it gives me something to hold onto when i’m rawing yer hard.” Sans took in a sharp exhale of breath at that, making Red chuckle. He continued rubbing his hands over Sans’s body, reluctantly moving from his breasts to travel south, leaving chaste kisses in his wake. Sans whimpered and whined underneath him from the stimulation, his dick twitching cutely in his panties in a way that turned Red on more than anything; he had to see it. Red went to pull down the garment, but Sans’s eye-lights widened when his hands brushed against the waistband.

“whoa, w-wait a second, pal.”

“wha? what’s wrong?” Red asked.

“uh, it’s--well, it’s a little...small,” Sans all but whispered the last part as he covered his crotch with a sheepish glance.

“babe, yer know this ain’t our first rodeo here right?”

“yeah, but--”

“and yer know that compared to me--” Red waved a hand in front of his body for emphasis-- “all of yer is small, right?”

“yes, bu--”

“then what’s the problem?” Red gently pried Sans’ hands from his crotch and took hold of his underwear, glancing up at him for permission. “this alright?”

Sans’s head flopped back onto the bed as he let out a sigh. “go ahead.”

Smiling, Red pulled the frilly underwear down to Sans’s knees, taking a moment to gaze at Sans’s cock. It was small like Sans had warned, probably smaller than what was considered average for someone of Sans’s size, but Red thought it was perfect: nice and cute like the rest of him. He could feel his own cock throb in his shorts from the delectable sight in front of him and he took a moment to palm it through his shorts, letting out a throaty groan from the pleasure.  

The sound caught Sans’s attention, and he glanced up at Red’s face. “do i really turn you on that much?” He asked.

“yer have no idea. i’m always imaginin’ yer underneath me, just like this, naked and filled with want. always thinking about how yer dick tastes in my mouth, and how yer body just spasms from being touched. and then yer face when yer orgasm, _fuckkkkk_ it’s so fuckin’ good. god, sans, i want yer so bad, can i?”

“ _shit_ red, fuck me,” Sans breathed, bucking his hips.

“heh, not yet,” Red replied, using one hand to hold Sans’s legs down. He dragged his tongue across his sharp teeth as he crept in close to Sans’s dick, brushing the head of it with a phalange. “first i’m gonna worship yer all over and make ya cum with my mouth, sound good?”

“Oh my god, _yes please_.”

With one last grin, Red lowered himself down between Sans’s thighs and got to work.

**Notes for the Chapter:**

> Thanks for reading! <3 feel free to bother me at my NSFW tumblr: [Sesurescue](http://Sesurescue.tumblr.com)


	4. Kustard Condiments Over Confessions - "It would be highly irrational for you to say yes, but I'd love it if you did."

**Summary for the Chapter:**

> Sans accidentally catches feelings

**Notes for the Chapter:**

> This prompt is from my Raffle for 400 followers, where I asked people to send in a prompt from a choice of several prompt memes and a fictional made up title. This one was sent in by AstaraGamer0125!
> 
> Pairing: Kustard (Sanscest, UT/UF Sans)  
> Prompt: “It would be highly irrational for you to say yes, but I’d love it if you did”  
> Other comments: "Please include one of the two confessing by somehow putting a message in the other's favorite condiment? (Then leading to *ahem* consensual smut with asphyxiation please?) <33333"
> 
> Tags: Classic Sans named Classic, Underfell Sans named Sans, Ecto genitalia, ecto penis, anal sex, asphyxiation, consensual friends with benefits relationship

Sans leaned against the outside of Fellby’s restaurant and checked his phone, scowling at the time. Classic was supposed to be there fifteen minutes ago, what the fuck. Sans always sent him messages at the last minute, and Classic had always been prompt, give or take a few minutes. What was different today?

He took a deep breath to calm himself, thankful that for once the blistering cold did something useful for him. He had to calm down; the only reason why he was so strung up was that he was horny and…

His pocket, which had already been heavier than usual, suddenly felt like a brick had taken up residence in it. 

This wasn’t supposed to happen. When Sans had first approached Classic with his idea, it had been real simple: casual fucks, booty calls, and absolutely, under no circumstances, were they supposed to bring feelings into this. In his universe, he couldn’t afford to let himself get distracted by fluffy sentiments and shit, especially not when he already had to make sure that he and Papyrus were alright. Sure, Papyrus may have had everything under wraps on his end, but he needed someone else to keep an eye out for him.

That someone had always been Sans, but lately, his thoughts had been clogged with his doppelganger. Sans couldn’t help but think about how Classic was, what he was doing, and most importantly, if he was thinking about Sans as well. Eventually, he couldn’t take it anymore and decided that he needed to confess once and for all. 

As he expected, Papyrus had been all for it. He’d had been hoping that they would get together romantically since the first time he ran into Classic in the hallway after a particularly rowdy night. The sap. Sans was sure that Papyrus expected him to confess like the Dating Manual taught him, with thorn-tipped roses and thinly-veiled adorations of love under threats. Surely some mindless fucking and confessions via mustard bottles were the next best thing, right?

The bushes across the way rustled slightly, and Sans instantly put up his guard, summoning his magic into a familiar canine shape--

“hold on, it’s just me,” A calm voice came from the shrub, and a second later a skeleton in a familiar blue hoodie tumbled out. 

Sans sighed in relief, dispelling his magic. He felt his mouth tilt up into a small smile before he squashed it, replacing it with a frown. “yer late.”

“sorry, wasn’t  _ egg _ pecting you to text me during breakfast. besides, the last time I initiated you were an hour late,” Classic added.

“pfft, yer right on that. now we’re even. come with me.”

“in here?” Classic asked dubiously, watching as Sans pulled out a key from his pocket. “does your Grillby know you have his key?”

No. “ye, it’s fine.” It wasn’t, and Sans had to hide in Fellby’s closet for hours until he could swipe the key from his bedside table, but his whole plan wouldn’t work without the restaurant. 

He opened the door, ushering Classic inside before locking the door behind him. While Classic busied himself at the counter, Sans went and closed all the curtains and blinds. The last thing he needed was for some stupid monster to come knocking because they saw some movement. 

When all that was done, Sans turned to Classic, and he felt his SOUL flutter nervously in his ribcage. He discretely pressed a firm hand against his pelvis, willing his magic to focus on that instead, before sauntering up to the counter. “hey darlin’, ready for the pounding of a lifetime?” He purred. 

Classic jumped in his seat, turning around quickly to face Sans. Behind him, an unfamiliar ketchup bottle clattered to a standstill on the bar. “Oh, that yers?”

“i...yeah. ketchup in your universe tastes weird, so i bought my own today.”

Weird, but who was Sans to say what was weird and not? He hadn’t tried the ketchup here, and those tale monsters seemed oddly picky about most things anyway. At least maybe this would make his own little item look less suspicious. He reached into his pocket, pulling out his mustard bottle and placed it on the counter beside Classic’s. “what a co-inky-dink. damn flame dick ran out of mustard recently. anyway, how yer wanna do it today?”

Classic reached out to grab the edge’s of Sans’s hood, yanking him close so that they were flush together. “dealer’s choice, remember?”

Getting back into the flow of things, Sans smirked as he ground his body against Classic’s, making sure that the hard-on in his shorts was apparent. “ _ haaa _ , yer right. what do i want to do to yer today...maybe a good fuckin’,” Sans said, punctuating it with another thrust. Classic moaned underneath him, and Sans could smell his residue magic in the air, knowing that it was starting to gather in his pelvis, ready to form whatever Classic needed. 

“mmm, yer know what? I want yer dick in me today, that alright?”

“o-oh? yeah, i can be down for that.” Classic pulled out from underneath Sans and switched their positions with a huff. “but uh, don’t we need--”

“don’t worry yer pretty little face, i got it right here.” Sans pulled out a small bottle and tossed it over. His cheeks burned from the casual slip-up of his attraction, and he forced himself to turn around, bracing his phalanges against the solid counter. The sound of the cap flipping open sounded louder in the quiet of the restaurant, and Sans felt his dick throb in anticipation. 

Okay sex, sex he can do. He could focus on this and not on the upcoming confession he’d have to do later. Perfect. 

Sans stiffened as Classic’s lube-covered fingers brushed over his entrance and he groaned softly. “don’t dawdle, i can take yer just like this.”

The fingers left his magic, and he heard Classic slather the liquid on himself. “alright, i just didn’t want to hurt you or anything.”

“come on, classic, yer know me better than that,” Sans guffawed.

Hands gripped the sides of his pelvis, and that was the only warning he got before Classic shoved himself into Sans’s ass. “you’re right,” Classic called over Sans’s moans. “i know that you like pain quite a bit don’t you, you freak.”

“ _ mmmm-- _ yer damn right i do.” Sans drove his hips back into Classic, setting a rough pace. He adjusted his angle and groaned loudly when Classic’s dick hit his sweet spot just on. “fuckkkk, do the thing,  _ please  _ do the thing!”

Classic slowed slightly as he lifted a hand from Sans’s hip to cup it around his cervical vertebrae. “you remember your safe word, right?”

“can’t forget it,” Sans replied, rapping his knuckles against the counter in the particular rhythm they decided on. “now fuckin’ choke me, yer third-rate comedian!”

Growling, Classic squeezed his phalanges tighter around Sans’s magic. Sans sobbed in relief, feeling his entrance clench around Classic as he finally,  _ finally  _ started to get the pleasure he wanted. 

The two kept up their thrusts, gyrating faster and faster as they began to approach their peaks. “classic--sans! i’m-- _ fuck _ \-- getting close!” Sans wheezed through his limited magic supply. He went to brace himself against the counter, and in his blissed-out state, he missed, accidentally knocking the condiments to the ground with a shatter. 

“ _ shit. _ ” The two of them exclaimed at the same time. Classic quickly pulled out of him, and the two of them waddled over to the other side of the counter to survey the damage. Sans, reaching the area first, avoided where the condiments mixed together into a brown murky mess as he used magic to clear the glass. “what a perfectly good waste,” he muttered.

It was then that he noticed something peculiar on the ketchup label. Were there words scrawled on the back? Curious, Sans reached for the label, nearly missing the soft gasp from behind him.

“wait, hold on a sec--”

“‘ _ we go together like ketchup and mustard’ _ ?” Sans recited. He looked over his shoulder at Classic, who was flushed a deep blue. “yer write this?”

“i, uh,” Classic stammered at a loss. He settled for a hesitant nod.

“well,” Sans chuckled, picking up the mustard label and showing Classic the back. “looks like great minds think alike, cuz i wrote the same shit, hoping yer would accept my new proposition. now,  **i know it’d be highly irrational for yer to say yes, but** , well,  **i’d love it if yer did.** ” 

Classic stared at Sans for longer than what was comfortable, but finally, he nodded. “yeah, i think i’d like that.”


	5. Kustard Caught Red-Handed "Will You Just Tell Me the Truth?"

**Summary for the Chapter:**

> Local trash skeleton bites off more than he can chew and has to deal with the wrath of his cute boyfriend, more at 7.

**Notes for the Chapter:**

> This prompt is from my 400 follower Raffle, where I asked people to send in a prompt from a choice of several prompt memes and a fictional title. This one was from Silverryu25. 
> 
> Pairing: Kustard (Sanscest, UF/UT Sans)  
> Prompt: "Will you just tell me the truth?"
> 
> Tags: Underfell Sans named Red, Fluff, SFW, Proposal (technically????)

Sans sighed, adjusting his jacket closer to his body. He really needed to consider getting something more suitable for the weather now that they were on the surface. ol’ reliable just wouldn’t cut it for him anymore. As he rubbed his phalanges together in hopes of gaining some sort of warmth, Sans glanced over at his brother, who looked to be in a similar predicament. Even in his freezing state, he couldn’t help but poke fun at Papyrus.

“hey, looking a little _chilly_ over there. thought the cold was _snow_ problem for the Great Papyrus.”

“SAANSS,” Papyrus whined, crossing his arms. “STOP MAKING FUN OF ME.”

“aw come on, paps, no need to give me the _cold_ shoulder.” Sans grinned, waiting for the infamous Papyrus meltdown™.

Luckily, Papyrus didn’t disappoint. He stomped his foot in the snow angrily, leaving behind imprints of his boot sole underneath. “SANS! YOU’RE...YOU’RE…”

Sans leaned forward, grin widening as he waited for Papyrus to continue.

“YOU’RE UN- _BRR_ -LIEVEABLE!”

“oh my god!” Sans wheezed out, nearly falling over from surprise. He must have been rubbing off on Papyrus more than he thought.

He continued to giggle into his phalanges, finding that every time he thought he finally it under control it would start up again. Even Papyrus was unaffected, letting out loud ‘NYEH’s every now and again.

Finally, after the two of them had settled back down into their normal state again, Papyrus turned to address Sans. “DON’T EXPECT ME TO DO THAT OFTEN, PUN WITH YOUR BOYFRIEND INSTEAD.”

“roger that.”

“SPEAKING OF WHICH, ARE YOU SURE RED WON’T BE ABLE TO JOIN US ON OUR SHOPPING ADVENTURE?”

Sans nodded. “said he was busy with Edge--er, I mean, his brother.”

“WHAT A SHAME. HE SEEMS TO BE QUITE BUSY THESE DAYS. GUESS WE’LL HAVE TO HAVE ENOUGH FUN FOR HIM.”

“heh, yeah.”

Papyrus began to walk in the direction of Main Street, and Sans followed him, deep in his thoughts. He didn’t realize it until Papyrus mentioned it, but Red had been increasingly busy as of late. Whenever he had proposed hanging out, Red said that he had to hang out with his brother. He knew that Edge, his snarky nickname for Red’s brother, was another version of Papyrus and needed a lot of attention and praise, but this seemed excessive.

Could it be that…Red was getting tired of him?

No, that’s not possible, Sans reasoned. He had to trust that Red was okay and that they were still okay as well. Besides, it was perfectly valid that Edge would start getting more clingy towards Gyftmas; he didn’t have enough of a relationship with Papyrus or the others to warrant hanging out with them, and he didn’t have a boyfriend of his own ( _yet_ , Sans thought with a smile. According to Red, Edge had been considering courting their Grillby.). If anything, Red was being a great big brother. How could Sans be mad at that?

As they got closer to Main street, Sans began to notice the holiday decorations. Multicolored string lights were lovingly wrapped around the stop signs and traffic light poles, bathing the snow around them in iridescent pools of light. Festive tinsel garland hung in doorways and pathways, and a unique wreath sat on every door they walked past. Even though humans seemed to celebrate a slightly different holiday than the monsters did, the decorations were much of the same, and Sans couldn’t help but grin at the nice reminder of home. He glanced at Papyrus out of the corner of his eye socket, practically hearing how excited he was through all the bone clattering and teeth chattering.

“S A N S! IT’S JUST LIKE HOME!” Papyrus screeched. He grabbed onto Sans’s arm and nearly dragged him onto the near the shops, eagerly glancing into each windowpane.

It was when Papyrus pulled Sans past a particularly dark alleyway that Sans saw something weird. A flash of black, and then a soft trailing magic line, tinted red. Something about it bothered Sans; it was familiar. “hey pap,” Sans said, patting Papyrus’s hand on his arm. “i gotta check out something real quick.”

Papyrus turned around in confusion, searching Sans’s face for clues. “ARE YOU SURE? WE JUST GOT HERE…”

“go ahead and look without me. it’ll give you a chance to look for my present anyway.”

“OH MY GOD???? YOU’RE RIGHT. OKAY, I WILL GO SEARCH OUT THE BEST PRESENT FOR THE BEST BROTHER EVER, WHILE YOU GO DO...WHATEVER IT IS YOU’RE GOING TO DO. MAKE SURE TO CALL ME IF YOU GET INTO ANY TROUBLE!”

Sans waved to his bro, lowering his hand when Papyrus got out of eye-light sight. He turned towards the alleyway and took a deep breath. He made a few tentative steps into the darkness, reaching out with his magic to sense any threats. Finding none, Sans went further into the alleyway, magic sparking to life in his eye, _just in case._

The alleyway was much larger than he thought at first, with winding turns and sudden dead ends. Sans had been ready to call it quits after ten minutes when he heard a heavy grunt from somewhere in the depths. He turned quickly and retraced his steps, kicking up snow as he nearly jogged towards the sound. His persistence paid off, for when he turned the corner, he came face-to-face with the sharp-toothed visage of his boyfriend.

Red yelped, taking a few steps back in surprise. His foot caught on something behind him, and Sans winced sympathetically as Red fell into the snow.

“you okay?” Sans asked. He made a quick Check on Red, sighing in relief when he saw that the HP bar was still full.

Red got to his feet with a groan. He glanced down at his jacket and brushed the snow off before glancing up at Sans. His grin was strained, and his eye-lights were focused somewhere behind Sans, instead of directly on him. “h-hey, babe. how’s it going?”

“going well, just out with papyrus shopping. how about you, how’s your bro?” Sans flicked his eye-lights to the ground, focusing on the object at Red’s feet. “is he in that trash bag?”

“nah, of course not. what do yer take me fer?” Red laughed nervously, scratching his chin. “he just wanted me to uh...take out the trash, yeah.”

“you’re like three miles from your house. also, you’re wearing a uniform for a trash collecting company under your jacket,” Sans pointed out.

Red looked down at himself, cursing under his breath. “this--er, it ain’t mine.”

“ **will you just tell me the truth,** red?” Sans felt himself get angry, properly angry for the first time in a while. It was just so _infuriating_ having Red, _his_ Red, lie to his face!  “why are you avoiding me? why are you out here in the middle of the night doing odd jobs? are you and edge struggling to make rent?”

“nah, nothing like that--”

“then _what_ is it, red? because i gotta say, it’s really easy to jump to some bad conclusions here.”

Red sighed, crouching down to sit on the garbage bag. “i had to take some extra jobs to get enough cash fer this. i wanted to surprise yer, but it can’t be helped.”

He reached into his pockets and pulled out a crumpled piece of paper, which he passed over to Sans. Sans opened it and nearly dropped the paper in surprise. It was a flyer for a popular jeweler’s shop in the area. There were different types of bracelets and earrings on the paper, but the only thing that had been circled several times in red was--

“a ring?” Sans asked. “for who?”

“oh my god--for yer, yer numbskull. who else would i be buying a ring fer?”

“but...it’s so expensive.” Sans wiped at his sockets, surprised to see tears glistening on his phalanges. Red noticed quickly and got to his feet, pulling Sans into a tight hug.

“shh, it ain’t too bad, babe. besides, yer worth every penny.”

Sans relaxed in Red’s hold, nuzzling his chin affectionately. “so, how long have you been working like this?”

Red hummed in thought. “a few weeks maybe. had a mail deliverin’ gig that sank real fast, and then i washed dishes fer a while. finally, i ended uh here, scavengin’ for trash in the alleyway to take to the dump. this is actually my last batch; after i take this in, i’ll have enough to buy this. i figured i have a good idea of yer ring size since we’re the same monster and all, but you wanna go with me to make certain?”

“sure. man, wait til papyrus hears about this.”

“oh,” Red whispered.  “don’t tell ‘em, but my bro was the first to know.”

“i can’t wait to see them argue over it.”

“right?!”

The two laughed loudly in the quiet alleyway, lacing their hands together before heading for the exit.

**Notes for the Chapter:**

> Wily-fox (18+ Tumblr) made beautiful [ fanart ](https://wily-fox.tumblr.com/post/177412854418/kusturd-from-drabble-caught-red-handed-by) for this fic! Please consider showing them some love! <3


	6. Kustard for Slimeybonez and Kustard Week: Day 7 (Naps)

**Summary for the Chapter:**

> where'd all the nice weather go ;n;

**Notes for the Chapter:**

> I wrote this for Slimeybonez as a thank you for a kofi donation a long time ago. This fic features Kustard and their ship kids, Boisen and Dewly. You can see them [ here! ](https://slimeybonez.tumblr.com/post/173809303593/i-wanna-thank-zionkilse-for-helping-me-with-their)
> 
> Established relationship, Slice of Life, Fankids, family fluff, picnics, naps, Kustard Week: Day 7 (Naps)
> 
> Fic based around this [ art ](https://sesurescue.tumblr.com/post/177523327398/slimeybonez-stay-cool-hot-weather-approaching)

It was a beautiful day outside. The birds were singing, the flowers were blooming, and the sun was out in full force, ready to greet everyone with its presence. However...

Why the fuck was it so bright out?

Red squinted up at the harsh twelve o'clock sun, grunting angrily. Sans wanted to go outside as a family, so the two of them packed a bag full of necessities, strapped in the kiddos, and went to the park. They had just arrived at the place and it only just occurred to Red that maybe they should’ve chosen a day that was more overcast. The sun was killing him! He dug into his shorts for some sort of buffer to put between his sensitive eye-lights and the death orb in the sky, and after a few seconds of shifting around the junk in his pocket finally found his favorite pair of rectangular shades.

Pushing up the brim of his cap to expose his cranium, Red slipped the frames onto his face and pressed the end pieces into the sides of his skull. The frames sizzled as they made contact with the bone, and once again Red wondered about this new adhesive. It was weird compared to the last one, smellier and slightly uncomfortable, but fuck was it effective. All it took was one touch and these bad boys wouldn’t move for anything, even--

“DA!” 

A tiny hand smacked his face, and suddenly his vision was full of purple. The hand tugged at his sunglasses, but true to their word they remained glued to his skull. Unfortunately, that meant his skull was pulled along with the glasses, making him stumble slightly.

Biting back a yelp, Red reached out and took hold of the wiggling mass of babybones in his face. 

“got ‘em?” 

“yea, i got the gigglin’ monster. they’re so active today,” Red remarked, sticking his tongue out at Boisen. The child in question nearly squealed as they clapped their hands together. They attempted to mimic the action with varying success, giggling manically.  

With a soft smile, Red lowered Boisen into the child sling around his front. The sling had been a gift from his brother, something that would allow him to keep both arms free to protect his family if he needed to. At first, he had been dubious on its use, but with a squirming sprout like Boisen, it became almost a necessity. Dewly on the other hand…

Red glanced over at Sans. Dewly was curled up against Sans’s chest, one fist clutching Sans’s collarbone as he snored softly. Sans had one arm supporting him and was using the other to rummage through their picnic basket. Red’s permanent smile tilted slightly downward and he walked over, stroking the top of Sans’s sunhat--Which looked so adorable on him. It had a purple flower on it that matched the flower crown Boisen was wearing and gosh how did Red get so lucky--with a gentle touch. “hey, lemme help yer with that.”

“oh, sure, thanks.”

Red crouched down beside Sans, clacking his teeth against his cheek affectionately before pulling the bag over. “what’re yer looking fer?”

“my um...shit, what was i looking for again?” 

Red put both hands over Boisen’s skull, gasping dramatically. “wow, babe, watch yer fuckin’ language around the young’ins.”

Sans gave him an exasperated look before rolling his eye-lights. “you’re one to talk. but seriously what was it…” Sans rubbed the side of his face while he thought, and after a few seconds his eyes grew wide. “my sunglasses, that was it.”

“didn’t yer put them…” Red searched one of the side pockets, letting out a small ‘aha!’ as he pulled out a pair of circular sunglasses. “knew i saw yer stash them there earlier.” He passed the glasses over to Sans, who took them gratefully.

“awesome, thanks.” Sans placed them carefully on his skull, pressing the taped ends down to keep them in place. Unlike Red, he stuck to the tried-and-true method of a strong piece of tape. “ready to go?”

Red nodded, getting to his feet. He picked up the picnic basket in one hand, and before he could move Sans sidled in close, looping their arms together. Sans placed a quick kiss to Boisen’s skull--much to their excitement--before smiling up at Red softly. “lead the way, husband.”

“oh my god, precious,” Red gushed, grinning widely back at him. The two of them entered the area and began to look around for a nice place to set up camp, preferably somewhere with shade. Luckily they quickly found a spot underneath a large tree, so Red set the basket down and pulled out a large blanket with flowers on it, their designated ‘picnic blanket’. With only a bit of interference from his favorite little troublemaker, Red managed to spread out the blanket on the ground. He took said troublemaker out of the child sling and placed them on the blanket, watching with amusement as they plopped on their behind and looked around with wide eyes.  

Sans took a seat beside Boisen with his legs out in front of him. He stroked their cheek, and then he maneuvered Dewly into his lap for a more comfortable snooze. “whatcha looking at, cutie? see something interesting?”

“mrrr…” Boisen replied, glancing back at Sans before patting the ground with their fist.   
  


“any idea what that means?” Sans asked, amused. 

“not a clue,” Red said. He lowered himself to the blanket, instantly sprawling over Sans’s legs, much to the other’s chagrin. 

“what do you think you’re doing?”

“gettin’ comfy.”

“yeah, but it ain’t comfy for me. get off, you’re heavy.”

“But yer loveeeee me,” Red crooned, placing a chaste kiss to Sans’s knee.

“i guess...oh babe, grab boisen.”

“wha--” Red turned around, watching as Boisen quickly crawled off the blanket and onto the grass. He stuck out his hand and channeled his magic, grabbing them with his gravity magic and slowly levitating them back. Predictably, Boisen found this hilarious and cackled as soon as they were back in Red’s arms. “gotcha, you little scamp.” He hugged them close to his ribcage, peppering their face in kisses. 

Red felt legs shift underneath him as Sans readjusted his position, and suddenly another weight was on his chest. He lifted Boisen into the air to investigate and found Dewly, surprisingly still asleep, clutched onto his bones like they were a lifeline. “oh?” 

“i wanna spend some quality time with boisen. plus you haven’t napped all day, might as well do it with a bud, right?”

“but...” Red was feeling quite exhausted now that Sans had mentioned it. He had been running around all day getting stuff together for their day out and playing with Boisen and Dewly while Sans took a nap. He’d honestly love to get some shuteye right around now, but he needed to be awake and vigilant. “what about th’ picnic?” He asked instead. 

“picnic,  _ smicnic _ . it’ll still be here when you wake up, now gimme.” Sans made a grabbing motion with his hands. Red looked into his eye-lights, sighing softly before passing Boisen to him. 

“yer know i can’t resist yer, cheater.”

“i just know how to play the game in my favor, no cheating involved,”  Sans remarked, smiling brightly as he brought Boisen close. “ _ hello sweetie, how are you? _ ”

“DA!” 

Red took in a deep breath, directing his attention to the snoozing babybones in his arms. Their face was tinted with their pinkish magic, small features scrunched up tightly as they snoozed. The large hoodie on their figure prevented Red from seeing the rise and fall of their chest, but he could feel the tiny breaths emanating from their half-open mouth. 

Red always found it hard to process how he could’ve helped produce such adorable bundles of joy, but here was proof, right in his arms. He resisted the urge to hug Dewly close to his chest in fear of waking them up, settling instead for a soft caress over the crown of their head. A yawn ripped its way from his mouth, and Red finally gave in to the fact that maybe he could use a nap. He had permission after all, why not take it?

“hey, sans?” Red called.

“mm?” 

“love yer.”

“love ya too, you big oaf. now go to sleep already.”

Red huffed, closing his eye sockets and drifting off into a soundless slumber. 

**Author's Note:**

> Thank you so much for reading! Please consider checking out the other Prompt Works in the Series!


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